Question

[Clearairturbulence]

In just a few lines, can someone explain 'Mcrit'.:confused:

[LME (GOD)]

A MacDonalds legal action????:E

[effortless]

Here you are (http://www.pprune.org/forums/showthread.php?threadid=10139&goto=nextoldest)

[Old Smokey]

Mcrit is the Mach Number at which the first part of the airflow over the aircraft reaches sonic speed, i.e. the Mach Number at which shock waves begin to form.

Having said that, Mcrit is normally quoted for the wing (although other 'fat' parts of the aircraft may reach it sooner).

It is NOT related to Temperature or Pressure Height.

It is ALMOST constant for any given wing, but may be slightly lower for a heavy aircraft flying at a high angle of attack, which implies greater acceleration of airflow required over the high AoA wing. (One more good reason to avoid flying too much above Optimum Altitude).

Regards,

Old Smokey

[Clearairturbulence]

Many thanks Old Smokey, just what I want.:)